On Monday's "The Late Show with David Letterman," Tom Hanks revealed that he has been diagnosed with Type 2 diabetes.   The actor said his drastic weight fluctuations needed for his changing movie rolls over the years may have been a factor.

For the film "Castaway," Hanks dropped 55 pounds.  On the other hand, for his role in "A League of Their Own," he gained 30 pounds.

Hanks told Letterman, "I went to the doctor and he said, 'You know all those high-blood-sugar numbers you've been dealing with since yu were 36?   Well, you've now graduated.  You've got Type 2 diabetes, young man.'" 

The veteran actor stars in "Captain Phillips,", which opens Friday in theaters nationwide.